1. Field of the Invention
The present invention relates to an exhaust system for an engine of a motorcycle including an exhaust pipe and a muffler.
2. Description of Related Art
An exhaust system for a motorcycle must reduce exhaust sound as much as possible. In this regard, separating the inside of the muffler into a plurality of expansion chambers which are communicatively connected by pipe dampens exhaust energy and reduces exhaust sound.
However, there is a problem in that disposing a plurality of communicative pipes in the muffler increases the weight of the muffler and deteriorates traveling performance.
In consideration of this problem, JP-A-Hei 6-264741 suggests a muffler for a motorcycle in which a space is formed by disposing an inner cylinder with a small diameter in an outer cylinder, forming a small pipe part is formed that concaves inside the inner cylinder, and filling the space with a sound absorbing member such as glass wool.
This construction reduces the weight of the muffler. However, because the space is communicatively connected to the small pipe part, glass wool filled in the space scatters outside by passing through the small pipe part, and exhaust gas enters the space from the small pipe part. Exhaust sound tends to leak outside from there, and thus a silencing effect may not be obtained satisfactorily.